I think I figured it out. Thanks CBari for putting me onto it. If you keep your foot off the brake and push the "ignition" button twice the truck goes through a start cycle except for engaging the starter. The preheat cycles just as if the truck was going to start and the fuel pump runs for about 20 seconds as indicated by the distinctive whirr of the pump, then turns off since the truck isn't cranking just like the 2003 did. So I think that's the way to prime it. Ken Irwin